Electronic regulator loops, e.g., voltage, etc., often use a power output device controlled by an operational amplifier in a feed-back loop (see FIG. 1). In order to achieve an accurate output value, both high gain and wide bandwidth are required in the loop. High gain improves the output line, e.g., voltage, regulation and wide bandwidth improves the response time to a sudden load change. However, high gain and wide bandwidth operational amplifier circuits pose stability problems. Existing approaches to obtaining stable high gain regulators having good regulation have been the use of gain boosting operational amplifier circuits, and/or nested operational amplifier circuits. The stability of the gain boosting operational amplifier circuits depends upon the external load characteristics. The nested operational amplifier circuit are stable because they have limited bandwidth, and thus produce poor load regulation.
Increased use of rechargeable high technology batteries such as Lithium Ion in electronic equipment have increased the desire for lower cost and higher performance voltage regulator and battery charging circuits requiring high-gain and high bandwidth error amplifiers in the control loops. Voltage converters also require high performance voltage regulators in their control loops.
Therefore, what is needed is an electronic amplifier circuit that enables improved line and load regulation at the same time. Preferably this electronic amplifier will achieve good stability while maintaining high gain (reduced loop error) and wide bandwidth (fast response to a load change.